New Delhi, India, July 27 (bdnews24.com/Reuters) - India's major cities were put on high alert on Sunday, with fears of more attacks after at least 40 people were killed in two days of bombings that hit Ahmedabad and Bangalore.

At least 16 small bombs exploded in Ahmedabad on Saturday, killing at least 39 people and wounding 110, a day after another set of blasts in Bangalore killed a woman.

A little known group called the "Indian Mujahideen" claimed responsibility for the Ahmedabad attack on Saturday. The same group said it carried out bombs attacks that killed 63 people in tJaipur in May.

It is unusual for any group to claim responsibility, but the government says it suspects militant groups from Pakistan and Bangladesh are behind a wave of bombings in recent years, with targets ranging from mosques and Hindu temples to trains.

"The entire nation, including major metro cities in India have been put on high alert and they have been asked to step up security in vital installations," a home ministry spokesman said.

In New Delhi, police used loudspeakers and distributed leaflets in crowded market places, warning people to watch out for unclaimed baggage and suspicious objects. Police guarded Hindu temples in Kolkata.

There were two separate series of bombings in Ahmedadad, the first near busy market places. A second quick succession of bombs went off 20 to 25 minutes later around a hospital, where at least six people died, police said. All were detonated with timers.

"I came with my two children to cheer up my mother admitted to hospital," said Pankaj Patel, whose son Rohan and daughter Pratha were killed at Ahmedadad hospital. "They were laughing when the blast occurred. Now they are dead."

Two doctors were killed in the hospital in a blast in which at least one bomb was tied onto a gas cylinder. Charred motorcycles and bicycles were shown outside. TV showed victims writhing in pain and covered in blood on hospital floors.

The other bombs were in Ahmedabad's crowded old city dominated by its Muslim community. Many were packed into metal tiffin boxes, used to carry food, and packed with ball-bearings. Some were left on bicycles.

Police found three other unexploded bombs in Ahmedabad on Sunday, local media said.

Ahmedabad is the main city in the communally sensitive and relatively wealthy western state of Gujarat, scene of deadly riots in 2002 in which 2,500 people are thought to have died, most of them Muslims killed by rampaging Hindu mobs.

Both Ahmedabad and Bangalore are in states ruled by the Hindu-nationalist Bharatiya Janata Party and are among the country's fastest-growing.

Gujarat's Chief Minister Narendra Modi is one of India's most controversial politicians, accused of turning a blind eye to the Gujarat riots.

MUSLIM BACKLASH?

Some analysts say there is evidence of local Muslim groups, for years seen as unaffected by the rise of global Islamist militancy, of taking up violence against India, where they are a poor and often neglected minority. They may be getting training and financial backing from Pakistan or Bangladesh.

"Over the last few years, the dissatisfaction among Indian Muslims has hitched onto the wagon of the global/regional jihad," said C. Uday Bhaskar, a security analyst and former director of New Delhi's Institute for Defence Studies and Analyses.

"If you have 150 million Muslims in India, only 0.0001 percent of that figure would mean a militant nucleus of 15,000 people."

Police raided one house in Mumbai where they believe e-mails from the Indian Mujahideen were linked, local media reported.

India's home ministry said on Friday it suspected "a small militant group" was behind the Bangalore attacks, while some police officials suspected the blasts could be the work of the banned Students Islamic Movement of India.

Some IT companies in Bangalore, known as India's Silicon Valley, were increasing security after bombs went off there. Each bomb had a similar explosive force to one or two grenades.

The city is a prominent software development centre and is also home to a major outsourcing industry.